1. Field of the Invention
This invention relates to an insulation barrier. More particularly, this invention relates to a method of making an insulation barrier for a roof insulation system as well as a ceiling system.
2. Description of the Prior Art
As is known, various types of insulation systems have been employed in building construction. For example, insulation systems have been known to use insulation materials in rigid and blanket form, for example made of wood, glass, urethane, polystyrene and the like.
In the case of roof insulations, it has been known that built-up roofs of asphalt have not been able to produce all the characteristics of an optimum roof. That is to say, built-up roof of asphalt is flammable, relatively heavy and of low insulation value. In order to improve the insulation qualities of a roof construction, use has been made of urethanes since such types of products provide a better insulation and are of relatively light weight. In addition, urethanes permit thermal drift and require ozone depleting blowing agents. Hence, urethanes tend to be of higher costs and are not as environmentally friendly as one would desire. In addition, urethanes being of open cell construction tend to absorb water.
It has also been known that expanded polystyrene can be used as an insulation material particularly since expanded styrene can be manufactured at relatively low cost, is stable, is easy to install and absorbs less water than urethane. However, expanded polystyrene does not have a flame-spread capability to permit use on roof deck assemblies that have metal decks. Instead, expanded polystyrene insulation must be separated from the metal deck by means of an approved thermal barrier, such as sheet rock, perlite, polyisocyanuate (PIR) or polyurethane (PUR). For example, guidelines that usually determine products that can be approved for roofing applications are set by local building codes. Some building codes follow the Uniform Building code which requires that a roof deck assembly with a metal deck substrate using expanded polystyrene (EPS) as an insulation board, must have a thermal barrier of 3/4 Perlite or 5/8 inch gypsum wall board installed between the metal deck and the EPS. Instead of using such wall board, any proposed roof assembly must successfully perform an insulated steel deck test. In this regard, there are two recognized agencies that perform an insulated steel deck test, one is Factory Mutual under F.M. test number 4450 and the other, Underwriters Laboratory under U.L. test number 1256.
Still further, it has been known to provide various types of substrates with coatings or the like in order to increase the flame and heat resistant characteristics of the substrate. For example, U.S. Pat. No. 4,647,500 describes a foamed plastic composition in which a coating of an inorganic binder composition is placed on the surface of the foamed plastic with or without the interposition of an elastomer coating. As described, the inorganic binder composition is liquid and comprises colloidal silica, monoaluminum phosphate and aluminum chlorohydrate. As an option, an alkyl tin halide catalyst may be employed to improve the bonding between the binder composition and the surface to which the composition is applied.
U.S. Pat. No. 4,702,861 describes a flame retardant coating which can be applied to various types of surfaces including synthetic resin foams in order to create a substantially continuous protective film so as to encapsulate and surface-envelope the structure onto which the composition is applied. As described, the coating is made from a working aqueous latex dispersion. In addition, the composition may be mixed with sodium silicate.
U.S. Pat. No. 5,035,951 describes a composition for retarding flame which employs a water soluble alkali metal silicate such as sodium silicate.
Similar coatings for flame retardation which employ sodium silicate, at least in part, are also described in U.S. Pat. Nos. 2,407,615; 4,179,535; 4,710,309; and 4,888,057.
Other materials have also been known for use in fire retarding composition such as hydrated aluminum silicate, as described in U.S. Pat. No. 3,490,065; aluminum hydroxide, as described in U.S. Pat. No. 5,034,056 and hydrated alumina or magnesium hydroxide as described in U.S. Pat. No. 5,215,581.
Still further, it has been known to provide a polyurethane foam with a coating of an intumescent material, for example, vermiculite coated with ammonium phosphate, such as described in U.S. Pat. No. 3,455,850.
Despite the knowledge of using coatings of various types on substrates as well as compositions in a substrate to enhance fire retardant characteristics, there has been no product on the market which employs a foamed polystyrene as a flame retardant insulation barrier particularly for metal roof decks.